3 Thermostat Problems That Impede Home Cooling and What to Do About Them

If your air home’s conditioner isn’t working properly, the thermostat is the first place to start troubleshooting. The thermostat is the nerve center of your home’s cooling system. If the thermostat is worn out or not set correctly, it can cause problems with the air conditioner, which you might think are more serious than they really are.

Three common A/C problems can be caused by a faulty thermostat or incorrect thermostat settings. Fortunately, many thermostat problems are easy to diagnose and fix, so you might be able to restore your home’s cooling system to its usual effective performance without the need for an expensive service call. Of course, you should call for professional HVAC repair services any time you’re not comfortable trying to fix a problem yourself.

Air Conditioner Won’t Turn On

If your air conditioner won’t turn on, try replacing the batteries if the thermostat is battery operated. Be sure the thermostat is set to “cool” mode and the temperature is set low enough to call for the A/C to come on. Look for a tripped circuit breaker or blown fuse. If you’re satisfied that the system is getting power, a faulty thermostat may be preventing the system from turning on.

Older manual thermostats can get dirty or wear out over time. Turn off the power to your air conditioner before you work on the thermostat. Pull the cover off and inspect all the visible parts of the thermostat. Clean accumulated dust and grease from moving parts and electrical contacts. Look for loose or disconnected wires. If the thermostat has a mercury switch, make sure the thermostat is level, since a mercury switch might not work properly if it’s not level.

Newer programmable thermostats can develop electronic problems due to manufacturing defects or age. If you clean and inspect the thermostat and are certain that all the wires are connected and the batteries are good, you might need to replace the thermostat.

A/C Won’t Maintain the Set Temperature

If your air conditioner doesn’t cool evenly throughout the day, or if you notice that rooms near the thermostat don’t get as cool as the thermostat setting, you may need to evaluate the placement of the thermostat and consider moving it to a better location.

The thermostat should never be mounted on the inside of an exterior wall, since the temperature along the inside of the wall will be influenced by outdoor conditions such as bright sunlight that might keep it from reading the actual temperature inside the room accurately.

Thermostats should be placed in the middle of interior walls where they’re exposed to air moving inside the rooms they’re in. They should not be placed behind open doors or behind drapes, since the air in those places will tend to be stagnant and not change temperatures quickly as the air conditioner runs.

A/C Turns Off and On too Frequently

Short cycling of the air conditioner can lead to early equipment failure and poor humidity control. If the air conditioner turns on and off much more often than it should, it could indicate thermostat problems rather than more serious equipment problems.

The thermostat can cause short cycling if the anticipator isn’t set to allow a sufficient temperature difference between the shut-off temperature and the temperature that turns the system back on. Ideally, your system should shut down at or just below the thermostat set temperature and then turn back on when your house warms up by several degrees. If you try to adjust the anticipator, make small changes and wait a few hours before making further adjustments.

Short cycling and failure to maintain set temperatures can also be caused by thermostat problems. Cleaning and leveling the old manual thermostat might improve its performance. Replacing the old thermostat with a modern programmable model might eliminate the A/C operating problems as well as save you money on your utility bills.

Learn more about thermostat problems, as well as Air Experts’ air conditioning solutions, or contact us at 919-480-2727

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